The ministry statement said the attorney general was considering prosecuting Sara Netanyahu for offences that include fraudulently procuring items, fraud and breach of trust.
A post on the prime minister's Facebook page published late on Thursday in response to media reports about a forthcoming announcement by Attorney General Avichai Mandelblit, said the claims against Sara Netanyahu were "absurd and will be proven to be unfounded".
It was unclear what political impact Friday's announcement might have on Netanyahu, who himself is under investigation in two corruption cases.
One of those, known as Case 1000, involves gifts that the prime minister and his family may have received from businessmen, while Case 2000 deals with alleged efforts by him to secure better coverage from an Israeli newspaper publisher.
Netanyahu - who has been prime minister for 11 years over four terms - has denied any wrongdoing.
Netanyahu leads a relatively stable coalition government and presides over a buoyant economy. His conservative Likud party has rallied behind him in the absence of clear rivals for the leadership, rebuffing calls for his departure from the center-left opposition.
Likud's religious-nationalist coalition partners, seeing no threat to their agenda with Netanyahu as prime minister, are likewise sticking with him for now.
In a case dubbed "the meals-ordering affair" by the Justice Ministry, Sara Netanyahu with help from an aide allegedly created a false impression between 2010-2013 that no cooks were employed at the prime minister's official residence, while indeed there were, according to the ministry statement.
This was done, the statement said, to procure state funding for outside catering that would have been covered had there been no chef.
"In this way, hundreds of meals from restaurants and chefs worth 359,000 shekels ($102,399) were received from the state fraudulently," said the justice ministry statement.
Sara Netanyahu has the option to plead her case in a hearing with the attorney general.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)